Εφόσον το ζητούμενο είναι το πρωτόκολλο S/PDIF:
S/PDIF was developed at the same time as the main standard, AES3, used to interconnect professional audio equipment in the professional audio field. This resulted from the desire of the various standards committees to have at least sufficient similarities between the two interfaces to allow the use of the same, or very similar, designs for interfacing ICs.[3] S/PDIF remained almost identical at the protocol level (consumer S/PDIF provides for copy protection, whereas professional interfaces do not), but changed the physical connectors from XLR to either electrical coaxial cable (with RCA connectors) or optical fibre (TOSLINK; i.e., F05 or EIAJ Optical), both of which cost less. The RCA connectors are typically colour-coded orange to differentiate from other RCA connector uses such as composite video.
The cable was also changed from 110 Ω balanced twisted pair to the already far more common (and therefore compatible and inexpensive) 75 Ω coaxial cable, using RCA jacks instead of the BNC connector, which is more common in commercial applications. S/PDIF is a consumer version of the AES3 format.
Signals transmitted over consumer-grade TOSLINK connections are identical in content to those transmitted over coaxial S/PDIF connectors, though TOSLINK S/PDIF commonly exhibits higher jitter.
Περισσότερα:
http://en.wikipedia.org/wiki/S/PDIF
Ο κάθε κατασκευαστής καλωδίων ακολουθεί αυτό το πρωτόκολλο, άλλος με καλύτερα αποτελέσματα κι άλλος με ακόμη καλύτερα, για τη συνδεσμολογία που χρησιμοποιούν οι εταιρείες κατασκευής συσκευών ήχου.
